Transfer mechanism for the sheet material of a multiplaten press

ABSTRACT

A transfer system for the sheets to be fed to and discharged from a multiplaten press which includes, at each press level, a support which may be disposed at a predetermined position corresponding to the trailing edge of sheet material in the press, detent means on the support, depressable by sheet material to be fed to the press on transfer trays, and abutment means for advancing the sheet material into the press over the detent means and finally into engagement therewith as a positioning member for the trailing edge. The device is thus able to position sheet material of various sizes at desired locations of the press.

United States Patent [151 3,695,464 Kaji 451 Oct. 3, 1972 [54] TRANSFER MECHANISM FOR THE 2,344,923 3/ 1944 Robinson ..214/16.6 SHEET MATERIAL OF A 1,766,251 6/1930 Greenleaf ..214/ 16.6 MULTIPLATEN PRESS 1,780,049 10/ 1930 Troyer ..271/54 [72] Inventor: Seiho a Aichbken Japan 2,831,213 4/1958 Klarrnann et a1. ....2l4/16.6 X [73] Assignee: Kabushiki Kaisha Meiki Seisakusho Primary Examiner-Evon C. Blunk Nagoya, Aichi-ken, Japan Assistant Examiner-Bruce H. Stoner, Jr. 22 Filed: Nov. 23, 1970 [21] Appl. No.: 92,003 [57] ABSTRACT A transfer system for the sheets to be fed to and [30] Foreign Application Priority Data discharged from a multiplaten press which includes, at each press level, a support which may be disposed at 21 Dec. 9, 1969 Japan ..44/99203 predetermined position corresponding to tha trailing edge of sheet material in the press, detent means on the support, depressable by sheet material to be fed to [58] Fie'ld 571/54 the press on transfer trays, and abutment means for '2371/84"l98/225 advancing the sheet material into the press over the detent means and finally into engagement therewith as a positioning member for the trailing edge. The device References cued is thus able to position sheet material of various sizes UNI STATES PATENTS at desired locations of the press. 3,531,003 9/1970 Kaji ..214/ 16.6 8 Claims, 11 Drawing Figures PATENTEDIJBI 3 1972 SHEET 1 0F 6 Seiho Kqji In men for.

B y g @395 w Attorney PATENTEDHBTB m2 sum 3 or 6 Seiho Kqji Inventor PATENTEU "E 3 I97? SHEET U 0F 6 Seiho Kcgji Inventor.

Attorney 7 TRANSFER MECHANISM FOR THE SHEET MATERIAL OF A MULTIPLATEN PRESS FIELD OF THE INVENTION BACKGROUND OF THE INVENTION In the processing of sheet materials, especially in the production of coherent sheets, boards or plates from less coherent mats and other raw layers, from laminated assemblies of layers to be bonded together, from sandwiched structures which are compressible and the like, it is known to make use of heated-platen presses between heated plates or platens of which the sheet material to be processed is fed, the material is compressed to .a rigid board structure, and the processed sheet material discharged.

The product of such presses may be fiberboards wherein the raw material is a prepressed sheet of particles, chips, shavings, fibers or dust of wood, cellulose or other material having a natural or an added binder which may be activated by heat. Depending upon the degree of heating, the pressure applied by the press and the nature and quantity of the binder, the product may be highly dense with excellent strength characteristics, may be highly porous or cellular with excellent insulating characteristics, or may be of any intermediate density with strength and insulating qualities between those already mentioned.

Another product of such processes is so-called sand wich board wherein one or more relatively dense layers constitute the surfacing of the finished product, while a less dense or lower-quality inner layer constitutes the body of the board. The inner body may be a stack of wood sheets or a fiber layer of the type mentioned above, a honeycomb of wood or other fibrous material or the like while the facing layers may be of wood and may, in turn, be covered with decorative laminates, the entire assembly being bonded together under heat and pressure between the platens of the press. Plywoods, veneers and other laminated structures :may also be products of such pressing systems.

In a single-platen press, the press may consist merely of the bed or bed plate and the head or head plate, one of which is shiftable in the direction of the other by hydraulic or other fluid-responsive means and possibly with the aid of mechanical devices. Since the pressing duration may substantially exceed the time necessary to form the sheet to be processed, it has been found to be advantageous to provide multiplaten presses in which a number of press operations are carried out in parallel and simultaneously. Such presses are known as multilevel presses, multiplaten presses, multistage presses, etc., and usually have at least two and possibly five to 50 horizontal platens disposed between the head plate and the bed plate. When a sheet to be processed is deposited upon each of these platens and the press closed, e.g., by lifting the bed plate hydraulically, each plated compresses the respective sheet between itself and the next uppermost press platen until the entire stack of sheets is compressed. To ensure uniformity of compression and avoid disadvantages which ensue when a sheet is omitted from one or more stages,

spacer means may be provided between the platens to define the thickness of the sheets to be compressed and/or the press may be provided with a simultaneous closure device whereby the platens are brought together uniformly as the bed plate is lifted.

Various transfer mechanisms have been proposed for the feeding of sheet material to such multistage heatedplaten presses. While the platens may be heated electrically, more often than not the heating is effected by the passage of a heating fluid, e.g., superheated steam, through the platens. The nature of the heating process is, of course immaterial to the present invention and is conventional in the art.

The known mechanisms for charging multiplaten presses are generally designed for material of a single size, i.e., for the introduction of sheets to be processed of a given size into the press for each pressing operation. When sheet materials of various sizes are to be produced, the transfer mechanism must be replaced or adjusted with care and by skilled personnel. Even with the adjustment, it is not always possible to deposit sheet materials of different sizes upon the platens in the press at the desired locations, it being understood that the press platens have a considerably greater area than most of the sheets pressed thereon by virtue of the fact that they must accommodate the largest sheets contemplated. Consequently, conventional transfer devices are often accompanied by further means for positioning the sheet material on the heated platens.

OBJECTS OF THE INVENTION It is an important object of the present invention to provide an improved transfer mechanism for conventional multistage or multilevel heating-platen presses for feeding onto the platens thereof sheet materials of varying sizes.

Another object of the invention is to provide a transfer mechanism of the character described in which the discharge of previously processed sheet material is effected in a more rational and convenient manner and in which the discharge of such sheet materials and the introduction of new sheet materials is accomplished by a single reciprocating movement of the transfer mechanism.

Still another object of the invention is to provide an improved transfer mechanism for the sheet material of a conventional multiplaten press having limited interplaten spacing.

Another important object of my invention is to provide an improved charging arrangement for a multiplaten press designed to correctly position sheets of varying sizes on the platens thereof.

SUMMARY OF THE INVENTION These objects and others which will become apparent hereinafter, are attained, in accordance with the present invention, with a transfer mechanism for a multiplaten press which comprises at each platen, a support member which can be disposed at a predetermined location vis-a-vis the desired position of the trailing edge of sheet material to be deposited in the press.

According to the invention, the support structure carries resiliently biased detent means which is designed to define a positioning surface for the trailing edge of a sheet to be fed into the press. The system also comprises an entraining means adapted to advance the sheet material into the press over the detent means, thereby deflecting the same downwardly until the trailing edge of the sheet passes over such detent means, whereby the detent forms the positioning member for the sheet. The entraining means preferably includes a tray designed to carry the sheet material against frictional retardation developed by the detent means which engages the underside of the material and a positive abutment engageable with the trailing edge of the sheet material for carrying the same over the detent means until the sheet material drops therebehind.

According to an important feature of the invention, therefore, the transfer mechanism comprises a supporting structure and a movable tray at each stage or platen of the press, the supporting structure being shiftable toward and away from the press. The detent or resilient means is provided at the forward side of the support structure and may be depressed below the upper surface of the tray and hence frictionally engages the underside of the sheet as the tray is shifted on the support structure. The tray is, therefore, reciprocably mounted on the support structure and provided with means for displacing it toward and away from the press in the direction of feed and in the opposite direction while having an abutment engageable with the trailing edge of the sheet material when the latter is retarded by friction.

The detent or stop means may be bodies having inherent resiliency, i.e., elastically deformable spring members with a thickness 2 at the free end and may be mounted on supports with a height h such that the detent means protrudes by a distance equal at least to t above the support. The sum h +t is equal to or less than the thickness H of the tray so that the resilient detent or stop means may be deflected within the thickness H of the trays by the sheet material sliding over the supports.

According to still another feature of the invention, the resilient means is one or more leaf springs extending in the direction of feed of the sheet material into the press and fixedly mounted at one end to the support structure. The free ends of the springs are bent downwardly and rearwardly and are biased normally upwardly so as to project over the upper surface of the transfer trays to a height which is less than the spacing between the platens. Hence the springs may lie in their normal upper positions when they are introduced between the platens of the press without interference with them.

DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a vertical elevation view, partly broken away and partly in diagrammatic form, of a transfer device according to the principles of the present invention;

FIG. 2 is a section taken along the line II II of FIG. 1 and showing one charging stage in plan view;

FIG. 3 is a vertical section representing a detail view of a charging system utilizing the principles of FIGS. 1 and 2 and illustrating a first stage in the transfer sequence;

FIG. 3 is a view similar to FIG. 3 in cross-section in the region of the detent means;

FIGS. 4 8 are view similar to FIG. 3 illustrating further steps in the operating sequence;

FIG. 9 is a plan view of another transfer device according to the invention; and

FIG. 10 is a cross-sectional view taken along the line X X of FIG. 9.

SPECIFIC DESCRIPTION Structure (First Embodiment) In FIGS. 1 3 and 3, I show a transfer mechanism co-operating with a multiplaten press P which has been illustrated in diagrammatic form and which comprises horizontal press platens 20 which are spaced apart by a distance D in the open position of the press and are vertically spaced apart. The platens 20 are heated, preferably by a fluid such as steam in the conventional manner. At the upper end of the press, a head plate 30 is mounted upon the posts 21 on which the platens 20 are guided by brackets 22. A bed plate 31 at the base of the press is shiftable vertically upwardly by a hydraulic system represented by the hydraulic piston or ram 32.

The transfer device comprises a support structure 1, carrying a plurality of movable trays represented generally at 12, the trays 12 being equal in number to the press platens 20 and being generally aligned therewith in a horizontal direction. The support structure 1 comprises a pair of rectangular frames 2, 2a interconnected horizontally by cross beams 8 equal in number to the trays and platens 20, each support beam having an upper surface which may be substantially aligned with the upper surface of the respective platen 20, i.e., is coplanar therewith, as can be seen from FIG. 3. The cross beams 8 are rigidly mounted upon the forward vertical posts of the frames 2 and 2a flanking the trays 12. When the press has six platens, for example, six cross beams 8 are secured to the posts of the frames 2 and 2a at their forward posts substantially at the same heights as the respective platens. In FIG. 1, for example, I show that the frame 2 has an upper beam 2', a lower beam 2" and a pair of uprights 2" at the front and rear ends of the assembly, the frame 2a likewise having this construction. A rigid body is established by means of the cross beams 8. It will be understood that the support provides a free space across which the transfer trays can be displaced without difficulty.

At each corner post of the frames 2, 2a, I provide a bracket arm 3 or 3a which rotatably supports a stub shaft 5 or 5a carrying a sprocket sheet 4 or 4a. Thus the four bracket arms 3 or 30 associated with each lever of the press each carry a sprocket wheel on the support structure. A pair of endless chains 6 interconnect the sprocket wheel to each side of a respective transfer tray, the chains being illustrated in dot-dash lines of FIG. 1. Each transfer device thus comprises a respective cross beam 8 upon which the transfer tray is slidable, the respective transfer tray 12 and a chain-drive arrangement which may be individual to the transfer means or may be common to them. In the system of FIG. 1, a common drive is provided with a pair of upper chains 6 and a pair of lower chains. The upper and lower chains on each side of the support structure 1 may lie in common vertical planes and may be interconnected by a vertical bar 13 connected to the movable trays 12 as will be apparent hereinafter. Since the chains at the upper and lower portions of the rack 1, 12 move in unison, the bar 13 is always vertical and since two sheets of chains 6 are provided on opposite sides of the rack, the structure 12 can be moved into the press without canting in the horizontal plane. The chain 6 may be driven by an electric motor and a further sprocket arrangement not illustrated.

In accordance with the principles of the present invention, a number of spring supports or rests 9 are mounted on each cross beam 8 and are offset or disposed alternatingly with the slats 16 and abutment pieces 17 of each tray 12. In other words, the tray 12 may comprise a support member 15 which bridges a plurality of slats 16 which extend in the direction of feed of the sheets and are parallel to one another in transversely spaced relationship in a comb-like array. The slats 16. lie midway between each pair of detent means 10. The slats l6 may have a length substantially greater than the width w of the sheet material to be handled and preferably in excess of the width W of the press platen in the direction of feed, the forward ends of the slats forming abutments designed to thrust the previously pressed sheet from the platen. Spaced rearwardly of the free ends of the slats and connected to the member 15, while projecting parallel to one another and to the slats are the abutment bars 17 which lie midway between each slat and the adjacent detent or resilient means 10. The abutment l7 lies above the receiving surface S formed by the slats 16.

On each of the spring supports or rests, there is fixed the resilient means in the form of a bent leaf spring 10 by means of mounting screws 11. The free end of the leaf spring 10, which extends parallel to the direction of feed of the sheets, is bent as shown by reference numeral 10a although, for convenience, a somewhat different bend structure has been illustrated in the diagrammatic view of FIG. 1. The bend includes an upwardly and forwardly inclined ramp l0b rising from the shank 10c which is held by the screws 11, in the direction of feed of the sheet material. A flat frictional surface 10d runs parallel to the receiving surface S and terminates in an abutment portion l0e which runs vertically downwardly and serves as a stop for the rear or trailing edge of the material. At its bottom, the bent portion of the leaf spring is turned through 90 inwardly as represented at 10f. The inwardly extending end 10f constitutes a re-entrant portion engageable beneath the end 9a of the spring support or rest 9 which projects in the direction of feed. Each of the transfer trays 12 comprises a pair of external frames or bars 14 interconnected by the bar 15 and extending parallel to the slats 16 already mentioned. The slats 16 are secured at their upper surfaces to the underside of the bar 15 in the embodiment illustrated in FIGS. 3 8. The upper surfaces of the abutment bars 17 are coplanar with the upper surfaces of the connecting bar 15. The sum of the height h of the spring supports 9 at their free ends and the thickness t of the leaf spring is selected to be equal to or less than the thickness H of the external frame 14 or the slat of the movable tray 12 as shown in FIG. 3.

To each of the frames 14 is affixed a rod 13, mentioned earlier, which engages a link of each chain 6 at the top and bottom parts ofthe rod 13. The free ends of the bars 14 and 14a and the slat 16 slidably rest on the cross beam 8 as shown in FIG. 2.

Operation The sheet material to be processed by the press is transferred, e.g., manually, from a stack or feed conveyor not shown, but located adjacent the supporting structure 1, onto the slat 16 of the transfer trays 12 over the connecting bar 15 and the abutment pieces 17. In this manner, a sheet 18 is placed upon every transfer tray 12 for which there is in the press a corresponding platen.

When the desired number of sheets 18 is deposited on the transfer trays 12, the support structure is moved on its wheels 7 (FIG. 1) until the free ends of the leaf springs 10 associated with the cross beam 8 are brought into contact with the trailing edges of the previously pressed sheet 19 (see FIG. 4 in which the leading or abutment surface of the slats 16 is represented at 16a and the trailing edge of the previous sheet 19 is represented at 19a).

Next the endless chains 6 are set into operation to shift the transfer trays 12 forwardly, i.e. in the direction of the arrows in FIG. 1 (i.e., to the right in FIG. 4); to drive the previous sheet 19 out of the press and bring the sheet 18 on the receiving surface S into engagement with the bent portion 100 of the leaf spring. The leaf spring is deflected resiliently downwardly (FIG. 5) and is wholly received below the surface S, as already noted. Continued motion of the members 14 16 brings the abutments 17 into engagement with the trailing edge 18 of the sheet material which is frictionally retarded by the portion 10d of the springs until engaged by the abutments. Once the engagement is complete, the sheet 18 is positively entrained with the tray 12 and moves to the right at the velocity thereof (FIGS. 5 and 6). The sheets 18, however, continue to rest upon the slats 16 which now overlie the press platen 20. As the trailing edge 18a is shifted beyond the leaf spring 10 (FIG. 6), the bent portion 10a jumps upwardly under its inherent resiliency so that the surface l0e projects above the receiving surface S by the distance t, to form an abutment for the trailing edge 18a of the sheet 18. The forward motion of the transfer tray 12 is thereupon terminated and the chains 6 are caused to rotate in the opposite direction, thereby retracting the trays 12.

As each tray 12 is retracted from the press, the corresponding sheet 18 engages at 18a the abutment portion 102 of the springs 10 extending above the respective surface S. Further movement of the trays to the left (FIG. 7) causes the sheet to deposit upon the platen 20 with the trailing edge 18a in engagement with the springs 10 thereby positively positioning the sheet at the location determined by the springs 10. After the tray (FIG. 8) is withdrawn to its original position as illustrated in FIG. 3, the press may be closed to subject the sheet material to compression with heating as is conventional with hot pressing in a multiplaten press.

SECOND EMBODIMENT Whereas the foregoing description has been connected with a reciprocable tray in which the bar 15 is affixed at its underside to the slats 16 to yield a tray structure of high strength, it is possible to design the tray somewhat differently according to the invention. In FIGS. 9 and 10, for example, wherein corresponding reference numerals designate functionally similar structure to that originally set forth, the slats 16 are secured to the front face of the bar 15. It is equally possible to secure the slats 16 to the top surface of the bar 15 as may be desired. In the latter case, the tops of I the abutment pieces 17 are secured to the front face of the bar 15 but project above the receiving surface of the slats.

In the construction of FIGS. 9 and 10, the abutment 17 is replaced by a resilient detent or abutment means, similar to that described at 10. This facilitates the insertion of the sheets 18 between the transfer trays and upon the rack. To this end, a leaf spring 23 is provided in alignment with each leaf spring 10 and has the configuration described with respect to the latter springs. The leaf spring 23 is supported by a support or a rest 24 which is welded to the bar 15. The leaf spring 23 projects forwardly beyond the front face a of the bar 15 and is secured to the latter by screws 15b, the upper surface of the bar being flush with the upper surface of the slats while the spring 21 has a bent free end 23a projecting normally above this surface. The spring sup port has a finger which is received above the downwardly and inwardly turned re-entrant end 23a of the spring 23.

When the sheet material 18 is delivered onto the tray 12 and its slats 16, the spring means 23 is depressed to a level corresponding to the horizontal upper surface of the tray 12 under the weight of the sheet material. When the sheet material shifts past the bent portion 23a, the latter forms a smooth abutment for the trailing edge 18a of the sheet and the tray operates in the manner described with reference to FIGS. l-8, the spring 23 forming an abutment equivalent to that shown in FIG. 7. The construction illustrated in FIGS. 9 and 10, of course, has the advantage that the effective thickness of the tray is less than that of FIGS. l8 by virtue of the fact that the upper surfaces of the bar 15 and the slats 16 are flush with one another. The system is of particular desireability where a large number of press platens are provided and the spacing between them is relatively small.

It should be appreciated that the sheet material to be processed by the multistage press is positioned on the press platens with a predetermined location of the trailing edge regardless of the varying sizes of the sheet materials provided, only that the breadth or width w of the sheet materials is smaller than the effective breadth or width of the transfer tray 12. This corresponds to a distance between the leading ends of the slats 16 and the abutments 17 or 23a.

The present invention thus provides a simplified mechanism for the transfer of sheet materials of different sizes which also serves to discharge previously supplied and processed sheet materials by pushing the same out of the press. Moreover, the transfer mechanism of the present invention has a small number of working parts and can be operated with substantially no defects and little need for repair, by contrast with earlier systems which were subject to frequent breakdown. In addition, the transfer mechanism of the present invention has the further advantage that the sheet material is transferred onto the press platen without coming into sliding contact with heated surfaces and remain in place once they touch the press platen. Adhesive agents or other foreign substances are thereby prevented from adhering to the underside of the sheet material.

The invention as described and illustrated will admit of modification in various respects which do not effect the scope of the invention as it is defined in the appended claims.

Iclaim:

1. A transfer mechanism for feeding respective sheet materials onto the respective platens of a multiplaten press, said mechanism comprising:

a support structure adapted to be positioned adjacent said press and provided with a plurality of support members each assigned to a respective level of said press; 1

resilient detent means on each of said support members; respective transfer tray assigned to each of said levels and reciprocable relative to the respective support member toward and away from said press and receivable between the platens of each level, said detent means projecting into the path of a sheet material carried by the respective tray and forming an abutment for the respective sheet material retaining same in said press upon retraction of the tray from the press, said detent means being deflected by the respective sheet material upon the passage thereof into the press upon the respective tray, each of said trays being formed with a plurality of slats defining a receiving surface for the respective sheet material, said detent means including a leaf spring projecting resiliently upwardly above said receiving surface in the absence of deflection by the sheet material and lying between said slats, each leaf spring having a thickness t and is received within a support structure at a free end of the leaf spring having a height h such that (h t) B H where H is the thickness of said slats.

2. The transfer mechanism defined in claim 1 wherein each of said trays comprises abutment means extending above said surface and engageable with a trailing edge of the sheet material for positively entraining same into the press, said leaf spring engaging the underside of said sheet material upon deflection thereby to frictionally retard the movement of said sheet material and bring said abutment means into engagement with said trailing edge.

3. The transfer mechanism defined in claim 2 wherein each of said leaf springs has a downwardly bent free extremity engageable with the trailing edge of each sheet material upon retraction of the respective tray from said press.

4. The transfer mechanism defined in claim 3 wherein said leaf springs extend in the direction of said press and are so arranged and constructed as to overlie platens thereof upon movement of said support into a position adjacent said press.

5. The transfer mechanism defined in claim 4 wherein said leaf springs have inherent resiliency.

6. The transfer mechanism defined in claim 5 wherein the collective height of the leaf springs and the respective support structures in an undeflected condition of each leaf spring is less than the distance between the platens of the respective level in an open condition of the press.

7. The transfer mechanism defined in claim 6 wherein each of said trays comprises a crossbeam and a comb-like array of said slats extending horizontally from said crossbeam and secured thereto, the crossbeam and slats of each of said trays having flush upper surfaces.

8. The transfer mechanism defined in claim 6 wherein each of said trays comprises a crossbeam and a 

1. A transfer mechanism for feeding respective sheet materials onto the respective platens of a multiplaten press, said mechanism comprising: a support structure adapted to be positioned adjacent said press and provided with a plurality of support members each assigned to a respective level of said press; resilient detent means on each of said support members; a respective transfer tray assigned to each of said levels and reciprocable relative to the respective support member toward and away from said press and receivable between the platens of each level, said detent means projecting into the path of a sheet material carried by the respective tray and forming an abutment for the respective sheet material retaining same in said press upon retraction of the tray from the press, said detent means being deflected by the respective sheet material upon the passage thereof into the press upon the respective tray, each of said trays being formed with a plurality of slats defining a receiving surface for the respective sheet material, said detent means including a leaf spring projecting resiliently upwardly above said receiving surface in the absence of deflection by the sheet material and lying between said slats, each leaf spring having a thickness t and is received within a support structure at a free end of the leaf spring having a height h such that (h + t) < OR = H where H is the thickness of said slats.
 2. The transfer mechanism defined in claim 1 wherein each of said trays comprises abutment means extending above said surface and engageable with a trailing edge of the sheet material for positively entraining same into the press, said leaf spring engaging the underside of said sheet material upon deflection thereby to frictionally retard the movement of said sheet material and bring said abutment means into engagement with said trailing edge.
 3. The transfer mechanism defined in claim 2 wherein each of said leaf springs has a downwardly bent free extremity engageable with the trailing edge of each sheet material upon retraction of the respective tray from said press.
 4. The transfer mechanism defined in claim 3 wherein said leaf springs extend in the direction of said press and are so arranged and constructed as to overlie platens thereof upon movement of said support into a position adjacent said press.
 5. The transfer mechanism defined in claim 4 wherein said leaf springs have inherent resiliency.
 6. The transfer mechanism defined in claim 5 wherein the collective height of the leaf springs and the respective support structures in an undeflected condition of each leaf spring is less than the distance between the platens of the respective level in an open condition of the press.
 7. The transfer mechanism defined in claim 6 wherein Each of said trays comprises a crossbeam and a comb-like array of said slats extending horizontally from said crossbeam and secured thereto, the crossbeam and slats of each of said trays having flush upper surfaces.
 8. The transfer mechanism defined in claim 6 wherein each of said trays comprises a crossbeam and a comb-like array of said slats extending horizontally from said crossbeam and secured thereto, the slats being affixed to the underside of the respective crossbeam. 